Aars District Heating Plant, Denmark

Waste-to-energy plant

25% increased energy production and lower operating costs

Furnace line 1 at the Aars District Heating Plant dated back to 1985-86 and required an excessive amount of down time due to clinker build-up. The plant was forced to close for two to four days every fifth or sixth week to clean the furnace room, losing valuable production time.

After investigating options for this plant, we redesigned both the water-cooled wear zone and secondary air system, and upgraded the grate to a new DynaGrate®. Wear zones were heightened using extra tubes and new, proprietary technology featuring cooling air inlet holes in the side walls and side panels.

With new wear zones energy production increased from an output of 6.5-7 MW to 8.5 MW.

The resultant minimal refractory wear and only minor clinker accumulation has led to an increase in productivity and a decrease in operating costs. Down time has dropped dramatically. Output has increased from 6.5-7 MW to 8.5 MW. This reflects 7.5 MW coming from the boiler and the remaining 1 MW coming from the wear zones themselves.

Furnace with the new patented water-cooled wear zone.

The rear of a furnace after 14 weeks of operation. The holes for cooling air can be seen in the bottom right-hand corner.

By cooling the sides of the furnace slag deposits are avoided as the wear zone is relatively cold. The costs for a wear zone are quickly covered with a payback time of as little as two years.